Water-tube boiler.



No. 7||,54e. Patented Oct. 2|, 190.2.-

.|.- E. VTHURNYCBOFT.

WATER TUBE BOILER.

:Application filed June 18. 1901.) (No Model.) 3 Sheets-Sheet I.

No. 7ll,546. Patented Oct. 2:, I902.

J. E. mormvcnon.

WATER TUBE BOILER.

(Application fild June 18, 1901.)

(No Model.) 3 Sheets-Sheet 2.

@Ze%%; I if m m: mums PEIERS cu nmou'mu. wAsl-unm'omp. c.

. No. 7l|,5 46. Patented'flctl 21,1902,

J. E. THOBNYCBOFT.

WATER TUBE BOILER.

(Apialication filed. June 18, 1901.) (No Model.) 3 Sheets-Sheet 3.

THE NORRIS Pains cu, PHOTO-LITHU.. WASHINGTON, n. c.

UNITED STATES PATENT OFFICE."

JOHN EDWARD THORNYOROFT, OF GHISWIOK, ENGLAND.

WATER-TUBEBOILER.

SPECIFICATION forming part of Letters Patent No. 711,5l6, dated October 21, 1902.

Application filed Tune 18, 1901- To aZZ whom it may concern:

Be it known that I, JOHN EDWARD THORNY- CROFT, a subject of the King of Great Britain and Ireland, residing at Ohiswick, in the county of Middlesex, England, have invented Improvements in Water-Tube Boilers, of

which the following is a specification. v In the specifications of former Letters Patents granted to me.viz., No. 669,562, No.

670,975, and No. 670,976-and in the specification of my application for Letters Patent,

Serial No. 729,299, I have described various constructions of water-tube boilers of the kind wherein water is caused to pass through'a number of. steam-generating elements arranged in parallel and each comprising a pair of water-tubes of large size that are arranged to extend from front to backof the boiler over a fire grate or grates and are inclined toward one another, the converging ends of each pair of tubes being connected together through a junction-box common to them and their diverging ends being connected at different. levels to a pair of headers or to a water-box, to which a number of other similar steamgenerating elements are connected. With such construction,owin'g to the comparatively large cross-section of the water-tubes, the heating-surface of each steam-generatingelement is small compared with the volume of the water in such element, so that a given volume of water has to pass many times through the element before it is wholly converted into steam.

The present invention relates to boilers of the type referred to, and hasafor its object to obviate the above-mentioned disadvantage and also to enable the heat of the hot gases to be transferred to the water in a more advantageous and eifective manner than heretofore, so that the water will be converted into steam more quickly than usual and the efficiency of the boiler increased.

With this and other objects in view the invention consists in certain constructions and in certain parts, improvements, and combinations, as will be hereinafter fully described and then specifically pointed out in the claims hereunto appended. I

In the boiler which has been selected to illustrate the invention the steam-generating elements each comprise two sets or groups of Serial No. 64,983. (No model.)

inclined water-tubes that are of comparatively small size and are connected at their converging ends to a common water-box having a removable cover or closure, so that access can be gained to all the tubes in the 'twt sets or groups and any one or more of such tubes can be withdrawn or replaced through.

the junction-box, the diverging ends of the two sets or groups of water-tubes being connected to a pair of headers orto awater-box. There maybetwo or more water-tubes in each set or group thereof, so that each j unction-box would be common to, say,'four or more tubes of smaller size than when only a single-pair of tubes is connected to the common junction-box, as in .earlier constructions of water-tube boilers of the kind referred to.

-By the construction described there will be Referring to the accompanying illustrative I drawings, Figure 1 is a longitudinal section,

and Fig. 2 a part cross-section,on the line A A of Fig. 1 and a part front elevation showing I one construction of water-tube boiler of the kind referred to according to the present invention. Fig. 3 is a similar view to Fig. 1, showing the invention applied to a modified construction of boiler of the kind referred to.

In the construction shown in Figs. 1 and 2 each steam-generating element comprisestwo lower water tubes a a, that are inclined upwardly and forwardly, and two upper watertubes 1) b, that are inclined upwardlyand backwardly, the converging ends of the four tubes being secured to a com mon j unction-box c and the diverging ends to a common waterbox 61. Fig. 2 shows how the space above the main combustion-chamber e and the chimney f is filledwith clusters of water-tubes a, b of small cross-section, between which are a number of comparatively large supplementary combustion-spaces g, through which the hot gas will flow in a zigzag manner and be brought into intimate and effective contact with the water-tubes. In the example shown in Figs. 1 and 2 the water tubes at I) are straight; but they may be slightly curved in the direction of their length, as shown in Fig. 3, in order to facilitate their expansion when heated and prevent their connections with the junction and water boxes 0 and at being injured by such expansion and also to admit of their diverging ends being secured in the inner wall of the water-box or headers d in a position nearly at right angles thereto. As will be seen, the junction-boxes c are inclined to the sides of the boiler, so that in conjunction with the zigzag arrangement of the tubes in the water-box d the vertical sets or groups of inclined tubes a a and b b of the superimposed steam-generating elements will come so close to the vertical sets or groups of the op positely-inclined tubes 17 b and a a, respectively, of the adjacent superimposed steamgenerating elements as to practically prevent hot gases taking a short upward course between the vertical sets or groups of tubes to the chimney f above, but will, on the contrary, be caused to move in a zigzag course between the tubes from one supplementary combustion-space g to another. h is a combined steam and water drum located at the front of the boiler and connected to the upper part of the water-box d by steam-tubes t'and water-return tubes 7;, these tubes 71 and 7c extending across the space above the watertubes and below the chimney.

Instead of connecting the diverging ends of the water-tubes a and I) to a common Waterbox cl, which may or may not be divided internally int-o vertical downtake and uptake chambers, they may be connected, as shown in Fig. 3, to a pair of lower and upper headers m and n, that are in the example shown arranged one in front of the other, the lower end of each header on being connected through tubes 0, a horizontal water vessel 1), and a downtake-tube q to the steam-drum h and the upper end of each header n being connected by tubes 7' to the said steam-drum.

In each example the tubes (1 a or b b in each set or group are shown arranged one above the other, with their axes in the same vertical plane; but they may be otherwise arranged, and more than two tubes may be used in each set or group.

What I claim is- 1. In a steam-boiler, the combination with a steam and water vessel, of a plurality of steam-generating elements each comprising two sets or groups of tubes inclined to one another and a junction-box common to both sets or groups of tubes and connected to the converging ends thereof, and means connecting the diverging ends of the tubes of each element to said steam and water vessel.

2. In a steam-boiler, the combination with a steam and water vessel, of-a plurality of steam-generating elements each comprising a cluster or group of tubes the tubes forming each group or cluster being connected to a common junction-box and the junction-box of each element being disconnected from the junction boxes of adjacent elements, and means connecting the ends of the tubes op posite to those which are connected to the junction-boxes to the steam and water vessel, whereby water enters a j unction-box through part of the tubes of a cluster and leaves it through the remainder of the tubes of the cluster, substantially as described.

3. In a steam-boiler, the combination with a lower main combustion-chamber, and an upper steam and water vessel, of clusters of water-tubes extending across the space above the main combustion-chamber, the tubes in each cluster being near together and arranged to form with adjacent clusters of tubes comparatively large supplementary combustionchambers through which hot gas will flow in a zigzag direction, and means connecting said tubes to said steam and water vessel.

at. In a steam-boiler, the combination with a lower main combustion-chamber, and an upper steam and water vessel, of a plurality of steam-generating elements each comprising two sets or groups of tubes inclined to one another and a junction-box common to both sets or groups of tubes and connected to the converging ends thereof, and means connecting the diverging ends of the tubes of each element to said steam and water vessel, said elements being arranged to extend across the space above the combustion-chamber and to form therein clusters of water-tubes of small section with comparatively large supplementary combustion-chambers between such clusters.

5. In a steam-boiler, the combination with a lower main combustion-chamber, and an upper steam and water vessel, of a plurality of steam-generating elements each comprising two sets or groups of tubes inclined to one another with the tubes in each set or group arranged one above the other and a junctionbox common to both sets or groups of tubes and connected to the converging ends thereof, and means connecting the diverging ends of the tubes of each element to said steam and water vessel, said elements being arranged to extend across the space above the combustionchamber and to form therein clusters of Wator-tubes composed of two vertical rows of tubes of small section with comparatively large supplementary combustion -chambers between such clusters, substantially as described.

6. In a steam-boiler, the combination with an upper steam and water vessel, a lower combustion-chamber, and a water-box connected to said vessel, of a plurality of steam-generating elements extending over said combustion-chamber and each comprising two sets or groups of tubes inclined to one another and connected at their diverging ends to said connected to the converging ends of the two sets or groups of tubes, the tubes in each set or group'being arranged one above the other, and tubes connecting the upper part of said water-box to said steam and water vessel and arranged at different levels, substantially as described. I

Signed at 77 Oornhill, London, E. 0., England, this 29th day of May, 1901.

JOHN EDWARD THORNYOROFT. Witnesses:

WM. 0. BROWN, EDMUND S. SNEWIN. 

